Mobile track tamping machine



Sept. 19, 1961 F. PLAssER ETAL MOBILE TRACK TAMPING MACHINE Filed Feb.24, 1959 United States Patent F 3,000,328 MOBILE TRACK TAMPIN G MACHINEFranz Plasser and Josef Theurer, both of Johannesgasse 3,

Vienna, A Filed Feb. 24, 1959, Set. No..794,930 Claims priority,application Austria Feb. 24, 1958 3 Claims. (Cl.-10412) The presentinvention relates to railway ballast tamping machines adapted to travelalong a railroad track from tie to tie to tamp the ballast under eachtie.

In known machines of this type, pairs of tamping tools are mounted on aVertically movable carrier so that the ends of the tools enter into theballast in the operating position of the carrier. Eflicient tampingmachines have been built with a plurality of pairs of cooperatingtamping tools mounted on separate carriers to tamp the ballast under theties about each rail. If the tamping pressure in this area isconsiderable, the ballast tends to be displaced laterally outwardly, thedensity of the tamped ballast underneath the ties being decreasedcorrespondingly by the ballast which is forced upwardly at the ends ofthe ties.

In our application Serial No. 691,360, filed October 21, 1957, nowPatent No. 2,969,749, dated January 31, 1961, we have proposed toovercome this disadvantage by mounting at least one tamping toollaterally of the machine so that it enters the ballast adjacent the endof the tie when the tamping tool carrier is lowered into its operatingposition. This additional lateral tamping tool participates in thetamping operation by exerting a pressure on the ballast, which isperpendicular to the tamping pressure of the cooperating pairs oftamping tools.

While such additional tamping tools somewhat prevent lateraldisplacement of the tamped ballast, they do not obviate the upwardescape of the ballast at the tie ends under the lateral pressure of thetamping tools upon the ballast.

It is the primary object of the present invention to eliminate thesideward as well as the upward displacement of tamped ballast.

We accomplish the above object by mounting a horizontal pressure member,such as a plate, on an additional tamping tool which is arrangedadjacent the tie end, the horizontal pressure member contacting theballast surface when the tamping tool carrier is lowered into thetamping position. In this position, the weight of the tamping toolcarrier rests on the horizontal pressure member and this alone willnormally prevent any ballast from escaping upwardly. In accordance witha preferred embodiment of the invention, however, the tamping tool withits horizontal pressure member may be vibrated to function as avibratory surface tamper and thus to fulfill the desired purpose withincreased efficiency.

According to another preferred embodiment, vertically yielding supportmeans is provided for mounting the additional tamping tool on thetamping tool carrier. This adapts the machine for different ballastheights while enabling the tamping tool carrier to be loweredsufliciently to permit the main tamping tools to carry out an elfectivetamping operation underneath the ties.

The above and other objects, advantages and features of this inventionwill be more fully understood with reference to the following detaileddescription of a preferred embodiment thereof, taken in conjunction withthe accompanying drawing wherein FIG. 1 is a schematic front view of thetamping mechanism and FIG. 2 is a schematic side view of the forwardportion of a mobile track tamping machine incorporating the combinationconstituting the present invention.

Referring now to the drawing wherein like numerals Patented Sept. 19,1961 2 refer to like parts, there is shown the forward portion of amobile track tamping machine with frame 3 supporting guide posts 2 onwhich the tamping tool carrier 1 is vertically adjustably mounted.Eccenter shaft 4 is mounted on the tamping tool carrier with its axistransverse to the track. Cooperating pairs of tamping tools 6 arecentrally linked at 7 with an adjustment mechanism (not shown) whichmoves the tools of each pair together and apart. This mechanism isimmaterial as far as the present invention is concerned and may take anyof the many known forms. While this invention is applicable to all typesof tamping machines with vertically adjustable tamping tool carrierssupporting cooperating pairs of tamping tools and the mechanism foroperating these tools forms no part of this invention, eflicientmachines of this type have been described in our U.S. Patents Nos.2,876,709, dated March 10, 1959, and 2,915,018, dated December 1, 1959,and, if desired, the lateral end tamping tools with their horizontalpressure member may be incorporated in machines of this type.

As shown, the upper ends of tamping tools 6 are pivoted to support arms5, the latter being vibrated by eccenter shaft 4. The other or lowerends of the tamping tools penetrate into ballast 9 along thelongitudinal sides of tie 8 when the tamping tool carrier is loweredinto the illustrated operating position, thus tamping or compacting theballast therebetween and under tie 8 in the range of the rail when thetamping tools are moved together while being vibrated during the tampingoperation.

All of the heretofore described features of the illustrated machine areconventional. In accordance with the invention, sideward and upwardescape of the tamped ballast at the end of tie 8 is prevented bymounting an additional tamping tool with a horizontal pressure plate 12on the tamping tool carrier 1. As shown in the preferred embodiment, theadditional tamping tool has the form of a conventional surface tamperincluding vibratory actuating means 10. As is well known, vibration maybe effected hydraulically, pneumatically, electrically or mechanically,such as by cam means.

Also in accordance with a preferred embodiment, the additional tampingtool is mounted on the tamping tool carrier by means of resilientsupport webs 11. The support elements 11 yield in a vertical directionso that the lowering of the tamping tool carrier to a desired tampingdepth is not impeded by the contact of pressure plate 12 with theballast, regardless of the ballast level.

The tamping machine of the present invention operates as follows:

The machine is moved into a position wherein tie 8 is centered betweenthe cooperating tamping tools 6. In this position, the machine isbrought to a halt, the tamping tool carrier 1 is lowered until thetamping tool jaws have reached a desired depth in the ballast. Then,eccenter shaft 4 and the tamping tool adjustment mechanism are operatedsimultaneously to eflfect tamping in a known manner. When the tampingtool carrier is lowered into its operating position, the pressure plate12 automatically makes contact with the ballast surface and pressesthereagainst adjacent the tie end. The vertical downward pressureexerted by the pressure plate 12, which is increased by vibration,counteracts the upward pressure of the ballast in this area, which iscaused by the tamping tools 6 compacting the ballast under the tie andthus forcing it laterally outwardly and upwardly.

After the tamping operation at one tie is completed, the tamping toolcarrierl is lifted along posts 2 and the machine is moved forwardly tothe next tie, where the operation is repeated.

While the inventionhas been described and illustrated in connection witha preferred embodiment, it will be A li understood that manymodifications and variations may occur to the skilled in the art,particularly after benefiting from the present teaching, withoutdeparting from the spirit and scope of the invention, as defined in theappended claims. a V

What we claim is: V i '1. A mobile ballast tamping machine adapted totravel along the rails'of a railroad track, comprising in combination:'avertically adjustable tamping tool carrier which may be loweredinto atamping position, at least one pair 10 of cooperating tamping toolsmounted on the carrier so that each tool of the cooperating pair oftools is positioned alongside the longitudinal sides of a tie to betamped and in proximity of oneof said rails when the carrier has beenlowered into the tamping position, an additional tamping tool mounted onthe carrier centrally in respect of said pair of cooperating tampingtools and laterally outside the end of said tie, and a horizontal presaV 4 a sure member mounted on said additional tamping tool and arrangedto contact the ballast surface when the tamping tool carrier is in saidtamping position.

2. The mobile ballast tamping machine of claim 1, comprising a resilientsupportmeans for mounting the additional tamping tool on the tampingtool carrier.

3. The mobile ballast tamping machine of claim 1, comprising means forvibrating the additional tamping tool in vertically yieldablerelationship thereto.

References Cited in the file of this patent UNITED STATES PATENTS1,555,194 Everett Sept. 29, 1925 1 2,847,943 Plasser et al Aug. 19, 19585 2,869,476 Kershaw Jan. 20, 1959 FOREIGN PATENTS 429,603 Germany June1,1926

